Thorax, Abdominal, Pelvis Flashcards
Rectus Abdominus
O: Internal- Crest of pubis to pubic tubercle
Medial- Anterior region of pubic symphysis
I: Cartilages 5th- 7th ribs, Xiphoid process of sternum
Inn: Intercostal n. (T5-T12)
A: Stabilizes pelvis, flexes trunk, compresses abdomin
External Oblique
O: 5th-12th ribs (outer surface)
I: linea alba, pubic tubercle, anterior iliac crest
Inn: Intercostal n. (T7-T12)
A: Unilaterally- Contralateral trunk rotation, ipsalateral trunk flexion
BIlaterally- flexes trunk
Internal Oblique
O: Thoracolumbar fascia, ASIS, iliopsoas fascia, iliac crest
I: 10th-12th ribs (lower borders), linea alba
Inn: intercostal n. (T7-T12), iliohypogastric n., ilioinguinal n.
A: Contralateral trunk rotation, flexes trunk
Transverse Abdominus
O: 7th-12th costal cartilage, ASIS, Thorocolumbar fascia, iliac crest
I: linea alba, pubic crest
Inn: intercostal n. (T7-T12), iliohypogastric n., ilioinguinal n.
A: Unil- ipsalateral rotation; bil- compresses abdomen
Transverse Thoracis
O: inner surface of sternum and xiphoid process
I: inner surface costal cartilage 2-6th ribs
Inn: 2nd-6th intercostal n.
A: weakly lowers ribs (expiration)
Innermost Intercostal
O: Lower margin of rib to upper margin of next lower rib, (costal angle to sternum)
I: same as origin
Inn: 1st-11th intercostal n.
A: lowers ribs, stabilizes chest wall, supports intercostal spaces
Internal Intercostal
O: lower margin of rib-upper margin of next lower rib (costal angle to sternum)
I: same as origin
Inn: 1st-11th intercostal n.
A: lowers ribs, stabilizes chest wall, supports intercostal spaces
External Intercostal
O: Lower margin of rib-upper margin of next lower rib (costal tubercle to interosseous junction)
I: same as origin
Inn: 1st-11th intercostal n.
A: Raises ribs, supports intercostal space, stabilizes chest wall
Diaphragm (costal, lumbar, sternal parts)
O: Costal- inner surface of 7th-12th ribs
Lumbar- medial L1-L3 vertebral bodies, intervertebral discs. Lateral- lateral and medial arcuate ligament.
Sternal- posterior surface of xiphoid process
I: central tendon
Inn: phrenic n (C3-C5)
A: Principle muscle or respiration. Aids in compressing abdominal viscera.
Psoas Major
O: Superficial- T12-L4 vertebral bodies and IV discs
Deep- L1-L5 costal process
I: Lesser trochanter
Inn: Direct branches from lumbar plexus (L2-L4)
A: Unil- lateral flexion
Bil- trunk flexion
Psoas Minor
O: T12,L1 vertebrae
I: Lesser trochanter
Inn: direct branches from lumbar plexus (L2-L4)
A: Weak trunk flexor
Quadratus Lumborum
O: iliac crest, iliolumbar ligament
I: lesser trochanter
Inn: T12, L1-L4 spinal n.
A: Unil- lateral flexion
Bil- expirtaion stabilizes 12th ribsIliacus
O: iliac fossa
I: lesser trochanter
Inn: femoral n. (L2-L4)
A: Flexes thigh and stabilizes hip joint
Obturtor Internus
O: Obturator membrane
I: greater trochanter on femur
Inn: direct branches of sacral plexus (L5-S1)
A: External rotation, Abd of flexed hip
Piriformis
O: Pelvic surface of sacrum
I: greater trochanter of femur
Inn: direct branches from sacral plexus (S1-S2)
A: External rotation, Abd of flexed hip
Coccygeus
O: Inferior end of sacrum
I: Ischial spine
Inn: Direct branches sacral plexus (S4-S5)
A: Supports pelvic viscera, flexes coccyx
Levator ani
O: Superior pubic ramus, pubis, internal obturator, fascia of levator ani
I: anoccygeus ligament
Inn: direct branches of sacral plexus (S4)
A: Pelvic Diaphragm, supports pelvic viscera
Ischiocavernosus
O: ischial ramus
I: crus of clitoris/ penis
Inn: pundendal n. (S2-S4)
A: Maintains erection by squeezing blood into corpus cavernosum
Bulbospongiosus
O: runs anteriorly from peritoneal body to clitoris (female)/ penile raphe (males)
I: Same as origin
Inn: pudendal n. (S2-S4)
A: Female- compresses restibular gland
Male- assists in erectionSuperficial Transverse Perineal
O: Ischial ramus
I: perineal body
Inn: pudendal n. (S2-S4)
A: closes urethra, holds organs in place
External Anal Sphincter
O: Encircles anus
I: same as origin
Inn: pudendal n. (S2-S4)
A: closes anus
